chuhan,
Sorry about your problem.
Unfortunately, with a myopathy, you have to know the cause of it first. Myopathy is just a general term that means there is a disorder of the muscles.
This can be in the general classes of a neuromuscular or a musculoskeletal disorder.
There is no one treatment for a myopathy. The underlying cause must first be determined. Then the treatment plan is devised based on the cause.
Hope you find the cause of your myopathy.
Good luck.